Allah, exalted be His praise, says: "Fighting has been prescribed for you though it is hateful to you; and it may be that you dislike a thing while it is good for you, and it may be that you love a thing while it is bad for you." [Surah al-Baqarah: 216]
Along with this, there are other verses of the Noble Qur'an in which the obligation of jihad is mentioned.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / Q17794